# 12: The Gravitational Field Flashcards

What is angular velocity?

The angle the object rotates through per second

what is the circular motion of an object

object moving in a circle with constant acceleration towards the centre

Why is a car travelling at constant speed in a circle, accelerating?

It’s velocity is changing since its direction is changing And acceleration = rate of change of velocity

In which direction is a car travelling in a circle, accelerating?

Centripetal acceleration is always directed towards the centre of the circle

What produces the centripetal acceleration and what does it do

Centripetal force, the force which acts at right angles to the direction of motion

In which direction does centripetal force act?

Towards the centre of the circle

what does the equation a = v^2 / r give and what type of acceleration is this what is v

the constant acceleration of an object towards the centre of the circle this is centripetal acceleration v is linear velocity

what is the equation F = mv2 / r for, what does it give

this is the equation for centripetal force, the force keeping an object in circular motion

why does linear velocity of particles increase as they spiral outwards, even though angular velocity is constant

v = r ω, ω stays constant but as the particle spirals outwards, r increases and so does v because of it.

why don’t we notice the spin of the Earth

our centripetal accel is so small and everything including us is moving at the same speed

What is a gravitational field?

A region where an object will experience a non-contact force, an attractive force to the object whose gravitational field it’s in

What does an object experience when you put it in a gravitational field of another object?

Experience an attractive force

What are gravitational field lines?

Arrows showing the direction of the force that masses would feel in a gravitational field of another object

What is a uniform field? How can you identify a uniform field with field lines?

A field that is the same everywhere. This is shown by the field line being equally spaced and going in the same direction

Point masses have a [] field (Point masses = ….)

Radial A mass where its assumed they act as if all there mass in concentrated at their centre

As a mass gets further from earth, what happens to the strength of the force it experiences? How is that represented in field lines?

Further - force decreases Lines of force are further apart

Why does a small mass in earth’s gravitational field not affect earth much?

Earth is so much more massive

What can you assume about the gravitational field at the surface of Earth? How is this represented in field lines?

Assume it is perfectly uniform So the field lines are parallel and equally spaced

The force experienced by an object in a gravitational field is always []

Attractive

What is gravitational field strength g?

Force per unit mass

A mass in a uniform gravitational field experiences a [] force

constant - because g will be the same everywhere